The certification of different mass fractions of DAS-81419-2 in soya seed powder : Certified Reference Materials ERM®-BF437a, ERM®-BF437b, ERM®-BF437c, ERM®-BF437d and ERM®-BF437e

This report describes the production of a set of Certified Reference Materials (CRMs) ERM BF437a, b, c, d and e, which are certified for their DAS-81419-2 mass fractions. This material was produced following ISO Guide 34:2009 and is certified in accordance with ISO Guide 35:2006. Genetically modified (GM) seeds of the soya event DAS-81419-2 and seeds from a non-GM soya variety were milled to obtain GM and non-GM seed powders with a similar particle size distribution. Mixtures of non-GM and GM soya powder were prepared gravimetrically. The certified value was obtained from the gravimetric preparations, taking into account the genetic purity with respect to the event DAS-81419-2 of the two powder materials and their water mass fractions. The certified values were confirmed by event-specific real-time PCR as an independent verification method (measurements were within the scope of accreditation to ISO/IEC 17025:2005). Uncertainties of the certified values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) and include uncertainties relating to possible inhomogeneity (Section 4), instability (Section 5) and characterisation (Section 6). The materials are intended for the calibration or quality control of real-time PCR measurements to identify DAS-81419-2 soya and/or quantify its mass fraction. As with any reference material, they can also be used for establishing control charts or for carrying out validation studies. The CRMs are available in glass vials containing at least 1 g of dried soya seed powder which were sealed under atmosphere of argon. The minimum amount of sample to be used is 200 mg. The CRMs were accepted as European Reference Material (ERM®) after peer evaluation by the partners of the European Reference Materials consortium.